Sectional overhead door

ABSTRACT

A sectioial overhead door is disclosed with a door leaf comprising several consecutive hinging panels (10, 10&#39;, 10&#34;) which are guided in the known way by rollers (11) in horizontal tracks and in tracks (12, 12&#39;, 12&#34;) joined to them to form a bow and are provided with a balancing device (15) in the form of approximately horizontal helical tension springs. The latter are designed to be space-saving, in particular with low drop heights, underneath the horizontal track sections extending into the building, such that on each of the outer side regions (27) of the horizontal track sections (12, 14) facing away from one another one or more helical tension spring units (16) are arranged approximately parallel to one another and one below the other. At least some of the helical tension spring units (16) consist of at least two coaxial helical springs (17, 18), the turns of which are mutually opposing and intersecting.

BACKGROUND OF THE INVENTION

The present invention concerns an articulated overhead door comprisingseveral panels linked together one after another in the direction ofmotion. The panels are guided by rollers at each end traveling in twosets of lateral tracks. The first set of tracks has a more or lessvertical section that merges into a curved section and then into ahorizontal section. The second set of tracks has a horizontal sectionthat merges into a downward-sloping section and then, next to thedoorway, into a vertical section. The horizontal section is positionedjust over and paralleling the horizontal section of the first set oftracks. All the panels except the one that is uppermost when the door isclosed are guided by rollers that travel in the first set of tracks. Thepanel that is uppermost when the door is closed is guided by rollers atthe upper edge. These rollers travel in the second set of tracks. Thedoor is balanced by a mechanism comprising more or less horizontalhelical tension springs, deflection rollers, and cables. One end of eachspring is secured to a part of the building extending away from thedoorway. The other end of each spring, the end extending into thedoorway, is fastened to a deflection roller. Each cable is fixed at oneend, wraps around a deflection roller, and extends to a pointestablished at one end of the bottom edge of the panel that is lowermostwhen the door is closed.

Articulated overhead doors are often preferred to unarticulated overheaddoors because they require less space inside the building to open andclose. They occupy less space above the doorway's lintel than a roll-updoor does. They are also easier to handle than vertically orhorizontally swinging doors, which require space both inside andsometimes outside the building.

Attempts have been made to get along with less space above the lintel byemploying what are called subsidiary tracks for the rollers that guidethe panel that is uppermost when the door is closed. Such tracks eitherextend over the horizontal sections of the tracks that the other panels'rollers travel in or are integrated into them as far as the sectionsthat face and slope down toward the doorway. A door-balancing shaft canbe mounted above such sections, and, even though the downward slopehelps to provide room for it, a lot of space is still needed above theupper edge of the doorway.

Mounting tension-spring mechanisms above (CH Patent 343 624) of below(U.S. Pat. No. 2,271,309) the horizontal section of the track instead ofa torsion-spring shaft behind the lintel has been suggested. Thisapproach, however, demands more overhead space, especially in a garage,or decreases the space at each side and below the horizontal sections oftrack.

SUMMARY OF THE INVENTION

The object of the present invention is accordingly an articulatedoverhead door of the aforesaid genus that will take up as little spaceas possible, especially above the lintel, and will leave space on eachside of the horizontal sections that extend into the building.

This object is attained in accordance with the present invention in thatthe springs are combined into modules, each comprising either a singlespring or a stack of two or more more or less parallel helical tensionsprings, on each outer side of the horizontal sections of track.

Mounting a spring module, and especially a stack of springs when moreforce is required, on the outer side of the track maintains the spaceabove and below the horizontal sections clear of door-balancingmechanisms. The space between the top of the horizontal sections and theceiling will accordingly be defined by the upper edge of the panel thatis uppermost when the door is closed as the panel moves. The space belowthese sections will be left extensively clear. The spring mechanismsmounted on the outer sides will keep the lateral installation spacerelatively small.

Some or all of the spring mechanisms in one particularly preferredembodiment of the present invention can include a pair of coaxialhelical springs. The outside coil diameter of the inner spring in such amechanism can be shorter than the inside coil diameter of the outerspring. The coils of the inner spring can fit between those of the innerspring. This feature eliminates the need for spacers between the coilsor for spring holders. The coils of one such spring can be right-handedand those of the other left-handed, in which case the coils of the outerspring will intersect those of the inner spring preventing those in onespring from engaging the gaps between two flights in the other spring.The springs can accordingly be positioned with their coils relativelyclose to one another. Of particular advantage is that such a spring canhelp to ensure safe operation by stopping free-flying fragments and wireends if the other spring breaks, eliminating the need for such specialsafety devices as core cables, telescoping jackets, etc.

Another advantage of this approach, which reduces the space needed fortensioning mechanisms by positioning one or more helical springs oneinside another or one engaging another is that it allows a particularspring characteristic, individual spring range, or total spring range tobe established on each side by installing several weaker springs in asmall space. Furthermore, a particular spring factor can be exploited toaffect the overall characteristic, and separate springs of varyingcharacteristic can be combined and paralleled.

Another way of adjusting the spring force on one side to the weight ofthe door is also provided to advantage in that the position of the endsof the spring mechanisms fixed to the building can be varied by forexample suspending a spring holder in a series of holes stamped out ofthe horizontal section of the track. Another and possibly additionalmethod of adjustment is to vary the height of the fixed holder thatholds one end of the cable. This approach is preferably and simplyembodied in the form of a series of openings that a holder, especiallyone that compensates for the different lengths of two parallel cords inorder to compensate for the distribution of load, can be inserted into.This measure will not only allow the load on the springs to be adjustedbut will also permit the individual cables to be cut to the same lengthduring installation. Symptoms of aging can also be corrected.

The helical tension spring modules can basically have hooks at each end.The springs, however, will preferably be flat-ended and operate inconjunction with holders of the species disclosed in Europe Patent 0 288061 B1.

The simple means of securing the weight-compensation mechanisms againstdamage from broken springs hereintofore described can be augmented withadditional means of ensuring safety. The cables that connect the ends ofthe spring modules attached to the door to the lower edge of thelowermost panel can be double. The two parallel and equally tensionedstrands wrap around correspondingly separate series of rollers at thecurve in the track, where they rest on resilient supports. The cables inone particularly preferred embodiment can be maintained equallytensioned in that their common ends are held against aweight-compensation mechanism that will accommodate any differences inlength between the two strands of the sort that especially occurs inoperation, allowing each strand to support its own share. A simpleweight-compensation mechanism of this type can be in the form of arocker that pivots back and forth around a shaft with stops distributedon both sides and along the cable and accommodating the end of the cableon each side. Appropriate for this purpose is an attachment whereby thewidened end of the cable engages a suspension as in a Bowden cable. Thestops will preferably extend along with the ends secured by themupstream of the shaft. In this event, any difference in the lengths ofthe two strands will tilt the rocker such that the angle allowed by thedifference will be more obtuse than when the stops are at the same levelalong the cable as the shaft or upstream of it.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the present invention will now be specified by way ofexample, whence further advantageous characteristics can also bederived, with reference to the accompanying drawings, wherein

FIG. 1 is a perspective view of the inner surface of an articulatedoverhead door with its tracks and with a schematically representedweight-compensation mechanism,

FIGS. 2a and 2b comprise a top view, respectively, and a side view, fromthe vicinity of the door itself, of the horizontal and bent down orcurved sections of the track,

FIGS. 3a-3e are a series of details of various embodiments of one ormore paralleled spring modules, each comprising two coaxial springs,along with a schematic section through one pair of springs,

FIGS. 4a and 4b are larger-scale, partly sectional side and top view,respectively, of part of one of the embodiment illustrated in FIG. 3b,and

FIGS. 5a-5f comprise larger-scale perspective views of various areas ofFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The articulated overhead door schematically illustrated in FIG. 1comprises a series of panels 10. The panel 10' that is uppermost whenthe door is closed and the panel 10" that is lowermost when the door isclosed differ from the other panels. All the panels except for panel 10'are guided by rollers 11 that travel in tracks at each edge of the door.Each track comprises a horizontal section 12, a curved section 12', anda vertical section. The rollers 11 that guide panel 10' are at its upperedge 13 and travel in a second set of tracks, each of which comprises ahorizontal section 14 and a section 14' that slopes down toward thedoorway, terminating in a bent-down section 14".

Such an embodiment, with two sets of tracks, is in itself known. Thedoor is provided with a weight-compensation mechanism 15 comprising analso in-itself known system of helical tension spring modules andassociated cables, whereby a helical tension spring module parallelseach horizontal section of track. One end of the spring modules issecured to the building, and the end toward the door to a deflectionroller. A cable wraps around the deflection roller. One end of the cableis secured at the lower edge of the lowermost panel and the other fixed,generally to the doorframe. The tension-spring mechanisms in accordancewith the present invention, however, are mounted on each of theoutward-facing sides of the horizontal sections 12 and 14 of the trackssuch as to occupy practically no space above or below the tracks.Furthermore, the volume of space occupied by the helical tension springmechanisms at each side is very small because all the helical tensionspring modules 16 required to balance the door or accommodate the forceand to keep the door up if a spring should break are paralleled andstacked. Furthermore, one spring in each pair is accommodated inside theother. The coils of each inner spring 17 are wound opposite the coils ofits associated outer spring 18 such that, as viewed perpendicular to theaxes of the springs, the coils intersect at an acute angle, as will beparticular evident from FIGS. 3 and 4.

The tension-spring mechanisms associated with each horizontal section oftrack and comprising one or more paralleled helical tension springmodules 16 are as will be evident from FIG. 5 fixed to the building atthe end of the horizontal sections 12 and 14 more remote from thedoorway. The sections are joined together at the end near the doorwayand provided with a deflection roller in the form of one or a pair 25 ofrollers. Each roller is provided with two parallel grooves. A cable 21is accommodated in each groove. Cables 21 extend parallel, with theirends practically against the same mechanisms, specifically on the onehand to a common point 22 established at one end of the bottom edge ofthe panel 10" that is lowermost when the door is closed, and on theother to the end of horizontal sections 12 and 14. Each cable extendsaround a direction-reversing roller 24 between each pair 25 ofdeflection rollers and point 22, allowing the position of that point tobe adjusted the motion of the door with respect to the fixed axes of thespring mechanisms.

The two views in FIG. 2 illustrate how helical tension spring modules 16are disposed in relation to horizontal sections 12 and 14. Eachschematically illustrated spring mechanism comprises two coaxial helicalsprings with opposingly wound coils. Also illustrated are the twoparallel cables associated with each spring mechanism. The side view inFIG. 2 is schematicized at the middle. The design and position of thehorizontal sections 14 and 15 of track and of one helical tension springmechanism comprising two stacked helical tension spring modules 16 willbe evident. The space left in the illustration by breaking off the sideview in the vicinity of the horizontal sections of track is occupied bya section perpendicular to the length of the tracks. Also evident fromthe side view in FIG. 2 is a series 40 of holes punched out of the endof horizontal section 14 toward the building. These holes are associatedwith a deflection-roller anchoring structure 37 secured to the end,inside the building, of a helical tension spring module 16 as will bespecified later with reference to FIG. 5.

FIG. 3 is a sort of exploded view illustrating how three differentembodiments of the tension-spring mechanism can be secured to the sidesof horizontal sections 12 and 14. One embodiment comprises a singlehelical tension spring module 16, another embodiment two parallelmodules, and a third three parallel modules. Each module comprises twocoaxial springs 17 and 18, with their midsections illustratedabbreviated. At each end of each embodiment, with one, two, or threespring modules, is a connector 30 comprising roller holders 35 and 36,spring-securing structures 31, 31', and 31", one for each spring module16, and deflection-roller anchoring structures 37 with flanges 38 and39. There is a top view of each such structure below its correspondingside view. How the springs in each spring module are attached to theholders will be specified hereinafter with reference to FIG. 4.

At the bottom of FIG. 3 is a longitudinal section through a springmodule comprising two coaxial springs, specifically an inner spring 17and a outer spring 18. As will be evident from the figure, the coils 20of one spring are wound opposite those of the other with respect totheir common axis 29 and accordingly intersect at an acute angle. Sincethe outside diameter Da of inner spring 17 is shorter than the insidediameter Di of outer spring 18, the springs can move independentlywithout any of the coils of one from entering the gaps between the coilsof the other, even though the difference Di-Da between the two diametersis short. To decrease the friction between adjacent areas of coils 20,they can be provided with a low-friction protector, a sleeve shrunk intobetween the coils or a jacket of low-friction plastic for instance.

FIG. 4 illustrates, with one end of a helical tension spring mechanismwith three helical tension spring modules 16 as a example, how thesprings are attached to a common flat connector 30. Connector 30 isprovided with three spring-securing structures 31, 31', and 31"extending toward the spring modules. The spring-securing structures arein the same plane and each has a narrower spring-securing section 32 anda wider spring-securing section 33 between it and the rest of connector30. As will be evident from the top and side views in FIG. 4, the outerspring 18 in each module 16, the spring with the long inside diameter,has been thrust over wider spring-securing section 33 toward the rest ofthe connector such that some of its coils 19 engage the backs of barbedprojections 34 on the edges 47 of the spring-securing section and canaccordingly be thrust farther in but not out. Inner spring 17, the onewith the short outside diameter, has been similarly thrust over thenarrower spring-securing section 32 and secured. Since narrowerspring-securing section 32 and its barbed projection 34 and anassociated depression 48 are at an angle of 180° to wider securingsection 33 and its projection and depression, it will be evident thatthe two springs are wound in opposite senses.

Mounted on the section of connector 30 more remote from spring-securingstructures 31 is a roller holder 35 comprising cheeks extending out ofconnector 30 and a counterbearing 36 suspended, as will be evident fromthe top view, in the connector.

FIG. 5 is a series of larger-scale details of FIG. 1. FIG. 5aillustrates the variable-length building-end attachment of a helicaltension spring mechanism comprising one or more parallel helical tensionspring modules 16 but represented in this event by a single spring. Adeflection-roller anchoring structure 37 of the species illustrated inFIG. 3 is secured to the end extending into the building.Deflection-roller anchoring structure 37 can be inserted into anydesired hole in a series 40 by means of a flange 39 that extends foward.Once flange 39 has been inserted, spring module 16 engages it behind thewall of horizontal section 14. Another flange 38, which extends oppositeflange 39, is provided with a bore. This bore comes into alignment witha punched-out hole next to one of punched-out holes that flange 39extends through once flange 38 is engaged. A bolt is then insertedthrough this hole and through the bore in flange 38 as indicated inFIGS. 5a, 5b, and 5c. Deflection-roller anchoring structure 37 ismaneuvered during this procedure by means of a suspension clip 46integrated into it.

FIG. 5d illustrates how the doorway-side end of each parallel cable 21is fastened at the edge of the door. The thicker ends 44 of the cablesare accommodated like Bowden cables in suspensions 43 and held in placeby the forces exerted on their associated pairs 25 of rollers by thespring modules. Suspensions 43 are mounted on a rocker 41 that pivotsaround an axis 42. Rocker 41 tilts to compensate for differences inlength between the two cables 21 and to accordingly distribute the load.To facilitate compensation, the suspensions 43 on each side of axis 42are farther from pair 25 of rollers than is the axis itself. To allowdistance adjustment of this attachment, rocker 41 can be inserted intoany desired opening in a series 45 extending along horizontal section14, and the particular spring forces and cable lengths can bere-adjusted as the mechanisms age.

FIGS. 5e and 5f show how the other, looped, end of cable 21 is securedto a point 22 at the lower edge 23 of the panel 10" that is lowermostwhen the door is closed and how direction-reversing roller 24 ispositioned and operates in the vicinity of horizontal section 14 and ofdownward-sloping section 14' near the building.

LIST OF PARTS

10. panel

10'. panel that is uppermost when the door is closed

10". panel that is lowermost when the door is closed

11. roller

12. first set of tracks, horizontal section

12'. first set of tracks, curved section

12". first set of tracks, vertical section

13. upper edge of panel 10'

14. second set of tracks, horizontal section

14'. second set of tracks, downward-sloping section

14". second set of tracks, bent-down section

15. weight-compensation mechanism

16. helical tension spring mechanism, spring module

17. inner spring

18. outer spring

19. overthrust coils

20. coil

21. cable

22. point of attachment

23. lower edge of panel 10"

24. direction-reversing roller

25. pair of deflection rollers

26. fixed cable end

27. side of horizontal section 14

28. building-end spring-module attachment

29. axis of spring

30. connector

31. spring-securing structure

31' spring-securing structure

31". spring-securing structure

32. narrower securing section

33. wider securing section

34. barbed projections

35. roller holder

36. counterbearing

37. deflection-roller anchoring structure

38. longer flange

39. shorter flange

40. series of punched-out holes

41. rocker

42. rocker axis

43. suspension

44. thicker cable end

45. series of openings

46. suspension clip

47. edge

48. depression

Di. inside coil diameter

Da. outside coil diameter

What is claimed is:
 1. An articulated overhead door comprising: aplurality of panels linked together in series in a direction of motion;rollers traveling in two sets of lateral tracks at each end of saidpanels for guiding said panels; a first set of said tracks having asubstantially first vertical section merging into a curved section, saidcurved section being connected to a first horizontal section; a secondset of said tracks having a second horizontal section merging in adownward-sloping section, said downward-sloping section being connectedto a second vertical section having a location nearest the door, saidsecond horizontal section being located above and parallel to said firsthorizontal section, all panels below an uppermost panel when the door isclosed being guided by rollers traveling in said first set of tracks,said uppermost panel being guided by rollers traveling in said secondset of tracks; door balancing means comprising helical tension springswith deflection rollers and cables, each of said springs having one endsecured at a location spaced from the door, each spring having anotherend extending into an area of the door and secured to one of saiddeflection rollers, said cables being grouped in pairs, one of saidpairs being adjacent each track, each of said cables being fixed at onecommon end and wrapped around one of said deflection rollers andextending to a point at one end of a bottom edge of a lowermost panelwhen the door is closed; modules combining said springs; at least aplurality of said modules comprising two coaxial helical springs with anouter coaxial spring and an inner coaxial spring, said coaxial springshaving coils wound in opposite directions and being connected togetherat both ends and being simultaneously subjected to loads; each of saiddeflection rollers accommodating one of said cables, said deflectionrollers being grouped in pairs, said cables having loads equallydistributed by at least one of said modules; and cable-tensioncompensating means fastened to said common end.
 2. A articulatedoverhead door as defined in claim 1, wherein said one end of saidsprings secured at a location spaced from the door has a variableposition along an axis of said springs and along said second horizontalsection by a series of openings extending along a track;deflection-roller anchoring means insertable into any one of said seriesof openings; flanges on said deflection-roller anchoring means andextending away from each other and away from said modules.
 3. Anarticulated overhead door comprising: a plurality of panels linkedtogether in series in a direction of motion; rollers traveling in twosets of lateral tracks at each end of said panels for guiding saidpanels; a first set of said tracks having a substantially first verticalsection merging into a curved section, said curved section beingconnected to a first horizontal section; a second set of said trackshaving a second horizontal section merging in a downward-slopingsection, said downward-sloping section being connected to a secondvertical section having a location nearest the door, said secondhorizontal section being located above and parallel to said firsthorizontal section, all panels below an uppermost panel when the door isclosed being guided by rollers traveling in said first set of tracks,said uppermost panel being guided by rollers traveling in said secondset of tracks; door balancing means comprising helical tension springswith deflection rollers and cables, each of said springs having one endsecured at a location spaced from the door, each spring having anotherend extending into an area of the door and secured to one of saiddeflection rollers, said cables being grouped in pairs, one of saidpairs being adjacent each track, each of said cables being fixed at onecommon end and wrapped around one of said deflection rollers andextending to a point at one end of a bottom edge of a lowermost panelwhen the door is closed; modules combining said springs; at least aplurality of said modules comprising two coaxial helical springs with anouter coaxial spring and an inner coaxial spring, said coaxial springshaving coils wound in opposite directions and being connected togetherat both ends and being simultaneously subjected to loads; said twocoaxial helical springs comprising an outer coaxial spring and an innercoaxial spring, said inner coaxial spring having an outside coildiameter that is shorter than the inside coil diameter of said outercoaxial spring, one of said coaxial springs having right-handed coilsand the other one of said coaxial springs having left-handed coilsintersecting said right-handed coils; common spring-securing means, saidcoils of said coaxial helical springs terminating in at least one commonend of said spring-securing means; said spring-securing means comprisinga first spring-securing section adjacent said coaxial helical springsand securing said inner coaxial spring, a second spring-securing sectionwider than said first section and securing said outer coaxial spring,said first and second spring-securing sections having edges with barbedprojections for preventing said coils from being pulled off from oversaid sections, and a common connector for integrating an equal number ofspring-securing means and said modules; said second spring-securingsection comprising a holder for holding said deflection rollers; meansfor anchoring said deflection rollers to said first horizontal sectionassociated with said deflection rollers; each of said deflection rollersaccommodating one of said cables, said deflection rollers being groupedin pairs, said cables having loads equally distributed by at least oneof said modules; and cable-tension compensating means fastened to saidcommon end; said cable-tension compensating means comprising a rockerfacing a pair of said deflection rollers and pivoting about a fixed axiswith means in form of a Bowden-cable suspension on each side of saidaxis for suspending a thicker end of the cable; said fixed end having avariable position along said second horizontal section by a series ofopenings; one end of said springs secured at a location spaced from thedoor having a variable position along an axis of said springs and alongsaid second horizontal section by a series of openings extending along atrack; deflection-roller anchoring means insertable into any one of saidseries of openings; flanges on said deflection roller anchoring meansand extending away from each other and away from said modules; one ofsaid flanges being longer than another flange, and one of said flangeshaving a bore.